Security update for qemu

SUSE Security Update: Security update for qemu
Announcement ID: SUSE-SU-2018:1386-1
Rating: important
References: #1068032 #1082276 #1092885
Affected Products:
  • SUSE Linux Enterprise Server 12-LTSS

  • An update that solves two vulnerabilities and has one errata is now available.

    Description:

    This update for qemu fixes several issues.

    This security issue was fixed:

    - CVE-2018-3639: Spectre v4 vulnerability mitigation support for KVM
    guests (bsc#1092885).

    Systems with microprocessors utilizing speculative execution and
    speculative execution of memory reads before the addresses of all prior
    memory writes are known may allow unauthorized disclosure of information
    to an attacker with local user access via a side-channel analysis.

    This patch permits the new x86 cpu feature flag named "ssbd" to be
    presented to the guest, given that the host has this feature, and KVM
    exposes it to the guest as well.

    For this feature to be enabled please use the qemu commandline
    -cpu $MODEL,+spec-ctrl,+ssbd so the guest OS can take advantage of the
    feature.

    spec-ctrl and ssbd support is also required in the host.
    - CVE-2017-5715: This update has the next round of Spectre v2 related
    patches, which now integrates with corresponding changes in libvirt. A
    January 2018 release of qemu initially addressed the Spectre v2
    vulnerability for KVM guests by exposing the spec-ctrl feature for all
    x86 vcpu types. We remove that initial patch and now rely on patches
    from upstream (bsc#1068032).

    This update defines spec_ctrl and ibpb cpu feature flags as well as new
    cpu models which are clones of existing models with either -IBRS or -IBPB
    added to the end of the model name. These new vcpu models explicitly
    include the new feature(s), whereas the feature flags can be added to the
    cpu parameter as with
    other features. In short, for continued Spectre v2 protection, ensure
    that either the appropriate cpu feature flag is added to the QEMU
    command-line, or
    one of the new cpu models is used. Although migration from older
    versions is supported, the new cpu features won't be properly exposed
    to the guest until it is restarted with the cpu features explicitly
    added. A reboot is insufficient.
    - A patch is added to continue to detect Spectre v2 mitigation features
    (as shown by cpuid), and if found provide that feature to guests, even
    if running
    on older KVM (kernel) versions which do not yet expose that feature to
    QEMU. (bsc#1082276)

    Patch Instructions:

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
    Alternatively you can run the command listed for your product:

    • SUSE Linux Enterprise Server 12-LTSS:
      zypper in -t patch SUSE-SLE-SERVER-12-2018-968=1

    Package List:

    • SUSE Linux Enterprise Server 12-LTSS (ppc64le s390x x86_64):
      • qemu-2.0.2-48.40.2
      • qemu-block-curl-2.0.2-48.40.2
      • qemu-block-curl-debuginfo-2.0.2-48.40.2
      • qemu-debugsource-2.0.2-48.40.2
      • qemu-guest-agent-2.0.2-48.40.2
      • qemu-guest-agent-debuginfo-2.0.2-48.40.2
      • qemu-lang-2.0.2-48.40.2
      • qemu-tools-2.0.2-48.40.2
      • qemu-tools-debuginfo-2.0.2-48.40.2
    • SUSE Linux Enterprise Server 12-LTSS (s390x x86_64):
      • qemu-kvm-2.0.2-48.40.2
    • SUSE Linux Enterprise Server 12-LTSS (ppc64le):
      • qemu-ppc-2.0.2-48.40.2
      • qemu-ppc-debuginfo-2.0.2-48.40.2
    • SUSE Linux Enterprise Server 12-LTSS (x86_64):
      • qemu-block-rbd-2.0.2-48.40.2
      • qemu-block-rbd-debuginfo-2.0.2-48.40.2
      • qemu-x86-2.0.2-48.40.2
      • qemu-x86-debuginfo-2.0.2-48.40.2
    • SUSE Linux Enterprise Server 12-LTSS (noarch):
      • qemu-ipxe-1.0.0-48.40.2
      • qemu-seabios-1.7.4-48.40.2
      • qemu-sgabios-8-48.40.2
      • qemu-vgabios-1.7.4-48.40.2
    • SUSE Linux Enterprise Server 12-LTSS (s390x):
      • qemu-s390-2.0.2-48.40.2
      • qemu-s390-debuginfo-2.0.2-48.40.2

    References: